XOD paradigm is a little different. You don’t have “variables” that can be stored/modified. You have “wires” that can pass data. The closest thing to a variable is a node like buffer; you can feed in any value, but output will only update when UPD pin is pulsed.

As shown in previous response, you can calculate values, but you don’t generally “store” that value in a variable, you just “wire” it to where it is used.